The prior art comprises numerous disclosures of controllers for electronic devices, such as a headset or another device connected to a headset cable. Some known controllers are arranged on a headset cable and they typically have rather small buttons or other control elements that are difficult for a user to locate and manipulate without looking at the controller. Large control elements, on the other hand, demand large controllers, which in many situations are unappealing or impractical. Some suggestions have therefore been made to provide sensors within the headset cable itself, so that portions of the headset cable can function as control elements.
U.S. Pat. No. 8,094,673 B2 discloses a cable for headphones that enables control of a device to which the cable is connected. The user may touch or apply pressure to the cable, either along the full length or to a localized part of the cable, in order to control the device. Pressure applied by a user can be translated to control of the device. A signal from the controller is interpreted to understand what action (gesture or type of touching) the user performed, such as e.g. sliding the user's finger, or fingers (including thumb), up or down the cable, rotating the user's finger(s) around the cable, pressing and holding with two fingers, or gripping and holding with the user's whole hand. The entire cable may be implemented as a capacitive control. Alternatively, the cable input device may include an additional wire and a conductive or semi-conductive sleeve. By squeezing the cable, the sleeve and wire make contact with each other, thereby completing a circuit like a simple mechanical switch. Alternatively, the cable input device may include a plurality of channels whereby one of the channels carries a high frequency signal (out of the audible range) such that when fingers pinch the cable, capacitive coupling to another channel occurs, which may be detected. The cable input device may be implemented as a piezoelectric pressure sensor, such that mechanical action by the user is translated to a measurable electrical signal. Touching the cable itself may vary a resistance being measured through the cable input device.
U.S. Pat. No. 8,116,503 B2 discloses a bend switch that can be incorporated in a wire and that can control one or more device functions without requiring a user to look at the switch. The switch includes two substantially co-linear elongated bodies that have contact surfaces that oppose each other and that, in an open switch position, do not contact each other. To close the switch, the user can bend the elongated bodies relative to each other such that the contact surfaces of the elongated bodies come into contact. When contact is made, a signal can pass from one elongated body to the other by passing through the contact surfaces. A movable space member placed between the elongated bodies may provide unlimited bending orientations or define preferred bending orientations. The contact surface may include several separated conductive portions that a user can selectively actuate. The switch may assist the user in bending the switch in orientations that cause specific portions of a contact surface to come into contact with the opposing elongated body, and different signals can be provided by each conductive portion when that conductive portion contacts the opposing elongated body. Software can process different types of signals provided by the switch to control different device functions.
US Patent Application US 2009/0257604 A1 discloses a deformable controller for controlling a portable electronic device. A user can interact with the controller to cause it to deform and thereby provide user input to control the electronic device. The controller may be an in-line controller with a cable that couples to the electronic device. The controller may include a deformable outer shell and a plurality of electrical contacts internal to the deformable outer shell. When the outer shell is deformed, outer electrical contacts come in electrical contact with a central electrical contact or with each other, and thus, the controller may provide a signal that allows initiating different commands in the electronic device depending on the user pressing, pinching, rolling, bending, sliding, squeezing, rotating or twisting the deformable controller. The deformable controller may further make use of force sensitive devices, tact switches, or touch sensors on or within the deformable controller. The deformable controller may determine a force with which the deformable controller is being deformed and use such to command an electronic device. In addition, a direction and a magnitude of a rolling action can be determined and a predetermined command may be initiated in accordance with the direction and magnitude.
European Patent 2 403 270 B1 discloses a cord-based controller for an auxiliary device, such as a headset, used with a portable electronic device. A pressure-sensitive, and preferably bendable, material such as a piezoelectric pressure sensor may be placed within or on an audio cable. A plurality of control sensor elements may be provided, each producing a different control signal voltage transmitted along a single control signal electrical connector. The controlling sensor may comprise a flexible voltage generating sensor, such as a piezoelectric sensor, and the control signal may be generated by deformation of the sensor material, independent of power supplied to the auxiliary device and independent of power supplied to the portable electronic device. The controller may differentiate between presses in different regions of the piezoelectric sensor by using areas of different thickness, thereby allowing multiple buttons along the length of the sensor-bearing cord without the need to include additional sensor pads.